AN EFFICIENT ALGORITHM FOR ELASTOVISCOPLASTIC VIBRATIONS OF MULTILAYERED COMPOSITE BEAMS USING 2ND-ORDER THEORY

An efficient time-domain algorithm for plane non-linear flexural vibra tions of multi-layered composite beams, which are driven into the inel astic range by severe transverse loadings, is presented The influence of an axial static preload is considered in the sense of the quasi-lin ear second-order theory of structures, The inelastic parts of strain a re treated as additional sources of selfstress in the linear elastic b ackground-structure, driving the elastic response into the inelastic o ne. The efficiency of this exact formulation lies in the fact that lin ear solution techniques can be used in their most powerful form: Rubin 's useful formulation for the quasi-static second-order transfer-matri x of linear elastic structures is applied in combination with modal an alysis. Having in mind multi-metal beams, the classical lamination the ory is assumed to be valid. Beams with overhang composed of ideal elas tic-plastic and viscoplastic layers are studied as example structures. The fictitious sources of selfstress are calculated from the differen t material laws of the layers in a numerical time-stepping procedure, where a generalized midpoint-nile in combination with Crisfield's seca nt-Newton procedure is used.